1. Field of the Invention
This invention relates to a steam iron that performs the ironing of clothes.
2. Description of the Prior Art
In conventional steam irons, water stored in a tank is supplied to an evaporation chamber where it is evaporated and discharged through an ironing surface. Water is supplied by dripping it from a nozzle at a limited rate so that the water is evaporated instantaneously as it is supplied to the evaporation chamber. A steam jet is started and stopped by opening and closing the nozzle, respectively.
Various types of steam irons that generate a momentary surge of steam in order to increase a fabric ironing effect have been proposed, typical examples of which are disclosed in U.S. Pat. No. 3,599,357 and U.S. Pat. No. 4,656,763, in which a pumping means is disposed to supply water from a tank to an evaporation chamber. The pumping means is provided with a cylinder which sucks up water from the tank and discharges it into the evaporation chamber and a piston which moves reciprocally in the cylinder. By repeating the manual vertical operation of a control button which controls the operation of the piston, water is forcibly supplied to the evaporation chamber temporarily in a larger quantity than is usually dripped at a limited rate, thereby spouting extra steam.
However, in such a conventional construction as described above, it is difficult to operate in an extra steam mode while a switching operation between steam and dry operation modes is being performed during ironing.
Ironing operation requires, in addition to well-balanced manual operation of horizontal iron movement and pressing down the iron for the pressing of the clothes, pressing down the control button which projects out of the handle against the spring force, when using the extra steam mode. Thus in addition to the strong pressing force required for the ironing operation, the operator must repeat vertical operation of the control button with a large stroke. This means that a great load is imposed on the hand and fingers, so that manipulation of the iron becomes poor.
Moreover, since these operations are performed at the discretion of the operator during ironing and the intervals and the speed of the operation are not constant the amount of spouted steam varies. And a supply of water in a quantity that exceeds the capability of the evaporation chamber to instantaneously evaporate the water causes a dangerous spout of hot water that has not been evaporated.
Furthermore, since the amount of spouted steam required for the finish of ironing varies depending upon the kinds of fabric to be ironed, and the operator controls the quantity of steam spouted at the discretion thereof by adjusting the interval and speed of the operation of the control button, it is very difficult to feed a stable supply of steam to the fabric, so that a good finish cannot be expected.